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m m. S P t e e h S 3 N E R G T L U H W a d 0 M m SAFETY VALVE PORHYDRAULIG ELEVATORS.

No. 443,208. Patented Dec. 23, 1890.

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No. 443,208. Patented Dec. 23, 1890.

.1.U. d a t E W \\x M m f m W m k f m V S Y I UNITED STATES PATENT Critics.

\VILLIAM H. HULTGREN, OF CHICAGO, ILLINOIS, ASSIGNOR OF ONE-HALF TO HERBERT A. BEIDLER, CF SAME PLACE.

SAFETY-VALVE FOR HYDRAULIC ELEVATORS.

SPECIFICATION forming part of Letters Patent No. 443,208, dated December 23, 1890.

Application filed July 6, 1889. $erial No. 316.708. (No model.)

To all whom it may concern.-

Be it known thatl, WILLIAM H. HUL'IGREN, of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Safety-Valves for Hydraulic Elevators; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification.

This invention relates to hydraulic elevators, and more particularly to auxiliary or safety valves for automa ically closing the I 5 water-passage leading from the main valve to the hydraulic cylinder when the elevator-cab, by accident or otherwise, reaches the extreme limit of its movement in either direction.

In the drawings, Figure l is a side elevation of an elevator-valve embodying my invention, the same being shown partly in section. Fig. 2 is a central vertical longitudinal sectional view of the auxiliary valve. Fig. 3 is a similar view of a modified form of valve embodying my invention. I

As illustrated in the drawings, A is a mainvalve cylinder, and B and C cylinders which form parts of devices for actuating or controlling the main valve,-and which are herein o denominated controlling-cylinders. Said cylinders A, B, and C are located in alignment with each other and preferably made of the same diameter. The valve-cylinder A is provided with a central annular port a, com mu- 3 5 nicatin g with the lateral discharge-passage A which leads to the operating-cylinder of the elevator. Within the said cylinder A are located two pistons D D, arranged at a somewhat greater distance apart than the width of the port a and rigidly connected with each other. The said cylinder A and the piston together form the main controlling-valve by means of which the influx of water to an exit of water from the operating-cylinder is gov- 5 erned. The said cylinder A is constructed in a well-known manner with a lining or bushing A affording bearingsurface for the pistons D D and provided with a plurality of parallel slots a to opening into the port a. The valve-cylinder A is opened at one end to the atmosphere, the end of the cylinder being commonly connected with a discharge-pipe for the water flowing from the 0perating-eylinder. At its opposite end the said cylinder A opens into or communicates with an annular space or port c, located between the cylinder A and the cylinder B and communicating with the water-inlet passage E, Fig. 1, which is connected with a watermain or other pipe supplying water under 6 pressure.

\Vhen the pistons D D are moved toward the discharge end of the cylinder A, water is admitted from the inlet-passage E through port a to the passage A, leading to the operating-eylinder, while by moving the said pistons in the opposite direction or away from the discharge end of the cylinder A commu nication between the passages E and A is closed, and the said passage A is brought into communication with the discharge end of the cylinder. By moving the said valve-pistons D D to the right or left, therefore, the flow of water to the controlling-cylinder and its exit therefrom may be controlled, as desired, while by placing the valve-pistons in an intermediate position communication with the operating-cylinder is entirely closed. The main valve is constructed and operates substantially in the same manner as similar valves heretofore employed for the same purpose.

\Vithin the controlling-cylinders are located suitable controlling-valves, which are connected with the pistons D D by means of a piston-rod D. F indicates the valve-chest of a pilot-valve. The said controlling-valves and pilot-valve are suitably connected with operating ropes or cables F F, which extend upwardly through the elevator-shaft, and one of which passes through the elevator, so that it may be grasped and controlled by the operator to operate the said controlling and pilot valves, which in turn actuate the main valve of the elevator.

The apparatus above described does not 5 form part of the invention claimed in this application, and the same is fully described and claimed in a separate application for Letters Patent, Serial No. 313,660, filed by me in the United States Patent Office June I00 10, 1889.

Between the lateral dischargepassage A of close the valve, and after the valve is closed the pistons will be left free to be moved backward a short distance, so as to partially open the valve, and thus allow a sufficient inflow of Water to start the piston of the hydraulic cylinder in its return movement.

The operation of the parts when the elevator is descending is just the reverse of that above described. I11 the descent of the elevator the water flows upwardly through the valve-casing. The piston-rod I moves to the right and causes the lug i to strike the lever, which moves thepiston-rod I and pistons to the right through a distance less than their full stroke. The force of the water in this case is exerted against the piston I and moves the same into the valve-seat g. In reversing the movement of the elevator after it has been stopped in this manner the pistons will be free to move backwardly by the action of the water thereon until the lever strikes the ing i when the movement of the pistons will be temporarily arrested until the movement of' the rod I shifts the said lug i backwardly a distance suiiicient to allow the pistons to move the full length of their stroke. The'movement of the pistons in both directions is limited by stops, which act to positively hold one or the other of the pistons in the valve-seat g. In the particular instance illustrated the inner surface of the head H forms a stop for contact with the piston I, while the inner end of the cap H forms a stop which is encountered by the piston I but the same result can obviously be produced by stops or shoulders otherwise formed or located on the valve-casing and shaft 1 or elsewhere on the movable or stationaryparts of the valve.

In Fig. 3 I have shown a modified form of construction embodying my invention, which is employed to prevent the piston from too suddenly closing the water-passage. In said figure the chambers H and H are constructed with bushings h h, within which the pistons I and I closely fit. A small water-passage 71 is formed in the wall of each of the said chambers and leads from the rear portion thereof to the interior of the valve-casing. It will be clearly seen that when either of the pistons enters its chamber it will confine the water therein, which can only escape slowly through one of the small water-passages 7L7, and thus retard the movement of the other piston in closing the main water-passage through the valve-casing. The main purpose of this last-described feature of construction is to prevent the cab from being stopped so suddenly as to bring an undue or dangerous strain on the elevator mechanism. The valve is opened after being automatically closed by reversing the direction in which the water flows through the casing G, it being entirely obvious that the pressure of water on the inner face of the piston which stands in and closes the valve-seat will move both pistons 'bacluvardly until they res'uiiic the position originally occupied by them.

One important advantage of the safetyvalve constructed as herein described is that after it has been automatically actuated to stop the elevator it may be opened from the elevator-cab by simply moving the main valve in the usual manner to reverse the direction of movement of the cab.

I claim as my invention 1. The combination, with the hydraulic cylinder of a hydraulic elevator, of a safety-valve mechanism comprising a valve located in the passage through which the water passes to and from the said hydraulic cylinder and having a movable valve-piston sustained normally out of the direct passage for water, and actuating devices connected with one of the moving parts of the elevator mechanism constructed to strike a part connected with said pistons and to move the latter through a distance less than the distance or throw required to fully close the valve when the elevator is near the extreme limit of its movement, and thereby shift the said valve-piston into the said water-passage, while leaving the piston free to be moved by the action of the water.

2. The herein-described safety-valve mechanism for hydraulic elevators, comprising a valve-casing located in the water-passage of the hydraulic cylinder and provided with a central valve-seat, two longitudinally-sliding pistons arranged in said valve-casing and held normally at opposite sides of the central valve-seat and out of the direct waterpassage, and actuating devices connected with a moving part of the elevator mechanism and adapted to strike a part connected with said pistons and to move one of said pistons toward said valveseat and into the water-passage when the elevator is near the limit of its movement in either direction, while leaving the piston free to be subsequently moved by the action of the water, substantially as described.

3. Theherein-described safety-valve mechanism for hydraulic elevators, comprising a valve-casing located in the water-passage of the hydraulic cylinder and two pistons therein, said valve casing being provided with a valve'seat and two chambers to receive said pistons, a longitudinally-sliding piston-rod supporting said pistons and having one end projecting outside of the valve-casing, and actuating devices connected with a moving part of the elevator mechanism and constructed to strike the said piston-rod and to move one of said pistons toward the said valve-seat through a space less than the stroke of the valve when the elevator is near the limit of its movement in either direction, while leaving the piston free to be subsequently moved by the action of the water, substantially as described.

4:. The herein-described safety-valve mechanism for hydraulic elevators, comprising a valve-casing located in the water-passage ot the hydraulic cylinder and two pistons in said casing, said casing being provided with a valve-seat and with two chambers to receive the pistons, passages for water leading from said chambers to points without the same, said pistons being titted to the walls of the chambers, and actuating devices connected with said pistons and with a moving part of the elevator mechanism and adapted to move one of said pistons out of its chamber and toward the valve-seat and the other piston from the valve-seat and into its chamber when the elevator reaches the limit of its movement in either direction, snlgistantir'illy as described.

5. The herein-dcseribed safety-valve mechanism for hydraulic elevators. COlllDFlHil'lg' a 'alve-easing located in the water-passage of thelrvdraulic cylinder and two pistons there- 1 in said valve-easing being provided with a' valve-seat and two chambers to receive said pistons, a longitudinally-sliding piston-rod supporting said pistons and having one end projecting outside of the valve easing, a vibrating, lever pivoted to said piston-rod, and two projections or lugs attached to a moving part of the elevator and which are adapted to strike and actuate said lever to move one 01' said pistons toward the valve-seat through a space less than the stroke of the valve when the elevator is near the limit of its movement in either direction substantially as described.

In testimony that I elai in the foregoing as my invention I attix my signature in presence of two witnesses.

\YILLIAM It. ll UL'IGRIC N.

Witnesses:

( CLARENCE PooLn, HARRY (Jone Kexxnnv.

J. D. RIPSOM. BURIAL GASKET.

2 Sheets-Sheet 1 (No Model.)

PatentedDec. 23, 1890.

M l i W 

